This article is about an ally in Uchuu Tetsujin Kyodain.Kenji Hayama (葉山健治, Hayama Kenji): The third and youngest son of Dr. Hayama. He is an elementary school and is far younger than his brothers Joji and Ryuji, who are both adults.
He was confused at first when Skyzel and Granzel came to the Earth in place of his brothers, thinking about his father and two older brothers who were taken to Dada by the Robot Army. The Kyodain gave him a walkie-talkie on his birthday. Even after reuniting with his brothers, he admired Kyodain and wept at the end.
He refers to Joji as "Big Brother" (Onii-chan) and Ryuji as "Small Brother" (Chini-chan).